Synthetic aggregate material and a process for producing same



cnoss REFERENCE 3' l-IMMINEB United States Patent gtcn r 3,503,771Patented Mar. 31, 1970 worn down or crushed under heavy impacts. Thepigment 3,503,771 is preferably a finely ground insoluble inorganicpigment,

SYNTHETIC AGGREGATE MATERIAL AND A PROCESS FOR PRODUCING SAME KarlKristian Kobs Kroyer, Vestre Kongevej 80, Viby, Jutland, Denmark NoDrawing. Filed July 18, 1967, Ser. No. 654,094 Int. Cl. C08h 17/04,17/68 U.S. Cl. 106-288 6 Claims ABSTRACT OF THE DISCLOSURE A synth t igaggregate material useful in rod surface coating's'comprises nodulesoLsmalLhodies of devitrified glass, hydraulically set cement and apigment. The aggrepigment admixed thereto, may be used. gate material isproduced by adding a mixture of cement and pigment to moistened smallbodies of devitrifie'd glass slhee the devlmhediglaes ordlharhy h whltematenal while stirring after which the resultant mixture is placedhelahvely Smah amhuhts ofplgmeht whhsuhice for cover on a moving surfaceto produce nodules which are reel fi hi h hi hlmtenal so as to theaggregate v ma er1a e esire co or. mo ed upon reachmg a predeterminedSize 20 The small bodies of devitrified glass have in themselves a highmechanical strength, and since the set cement has This invention relatesto a synthetic aggregate material e good Strength prhperhes the nodulesfermed of both which is particularly suitable for use in moldable roadsur- Y have a gheat resletahhe to meehahleal mhheheee- Ah f coatingsimportant factor attr buting for the good strength prop- In recent yearsa need has arisen of making road surface a erhes the nodules is thatfact that h Smah bodies of coatings in colors other than the black-whiteshades hitherdevhhhed glasshave sharp and W111 therefore h to to used,partly for aesthetic purposes and partly for the be thoroughlymterehgaged hhnhg e hodhle formation purpose of directing the throughtraffic through urban The sharp edges of the bodies of devitrlfied glassare also areas where it is difficult to place road signs in asufficiently of hhpertahee the P where aggregate matehal 1e conspicuousmanner. Such directing of the traffic may e.g. he used in road Surfaceehahhgs because the nodules be obtained by providing differently coloredguiding strips wlh have a rough sahdphper'hke h h as eohseqhehee orlanes in the road surface coating of larger or smaller grains ofdevitrified glass protruding o way of providing colored asphaltcontaining road from the surface. When the nodules have beenincorposurface coatings or parts thereof, such as traffic strips is tohated m a road surface eoahhg ahd the asphalt h use colored asphalt.However, this solution has the drawmg the nodules has been F P by theWear Yeslhhhg back that the color eifect obtained will be relativelyslight, from the hedhlee whl give e road he rough because the asphaltwhich constitutes the binder of the character and the multitude h gramsof devlmhed glass asphalt road surface coatings amounts to only about10% Pretrhdlhg m the hhdhlee wlh make the'hodhlee h 0f the coatingMoreover, a great proportion of the rah, 4n ishable and W111 therebyensure good frictional properties tively soft asphalt is removed by wearso that the color of the reed Shrhaee eoahhg- 'e nodules ate vanishes ina relatively short tin capable of breaking the water film which isformed on the It has also been attempted to use colored natural mate-.road surface In mole? f rials as aggregate materials in the constructionof roads. The hggregaie maiehal aeeorhhg the lhvehhoh h This solutionhas not been satisfactory either, because it {also a good reelstahee toe chemical lhhhehees' whleh has been very difiicult to find materialshaving the desired i may be Shhleeted when Incorporated 1h mateheis usedcombination of strength and color. the atmosphehe since the aggregatematerials most Commonly used f The small bodies of devitriiied glass mayhave a partic e asphalt road surface coatings, such as granite,calcinated Slze h the Inmate nodules h Prefer? fiint and devitrifiedglass, are not directly susceptible to fhade whh a gram h of ih44241159" f range coloring, it has been considered to color thesematerials by mg h fohhd Parhehlarly $155k for h 1h road ehrfheeproviding them with a colored glaze However, the use f coatings.However, for special purposes it may be desirable a glazed aggregatematerial for road surface coatings or to Produce even greater for thecoating of other surfaces that are subjected to heavy Aeehrdmg toPreferreh emhhdlmeht of the aggll'egate influences in the form of wear,blows and great variations e i aeeerhhg he the lhvehheh; the ih e of oftemperature is not satisfactory because the brittle glaze devlh'lhedglass are made by qhehehlhg of molten 3.1351513t may easily burst offthe base material whereby the 1 has been found that the glass particlesformed in this man- I efiect is 1051:. Moreover, the glazing is a bothtime consuma extent hheleahy a ehhle l f ing and expensive processbecause it requires heating to Thls ehble shape'ls p 'f y sultflblfi forthe malellal high temperatures 60 according to the invention, becausethe small bodies will It is the object of the invention to provide aninexpensive F have a great umber sharp edges hmhel' ehhh'lbut'wear-resistant colored aggregate material. 8 m the a sp abovfi' I Withthis object in view, according to the invention, an s e sdevlh'lhedglass to eemehP aggregate material isprovided which consists of nodulesprefefflbtyhebeflihllbxbut hlghel' 9 P P of smallbodies of devitrifiedglass, hydraulically set y used aeeol'dlhg to the l'equll'emcmfl incement and a pigment. The color effect obtained with the lhdwldualeaseuyat ls is P ly aggregate material according to the invention isproduced about 41 1 its-29.1%;sansat, whe y the cement by the pigmentwhich is uniformly distributed in the have the highest P0555151eStrength and the lowest Possible cement mass, which serves to unite thesmall bodies of P Y- This Proportion y, fl', be changed devitrifiedglass in the form of nodules. Consequently, the 7 according to therequirements in each individual case, and

aggregate material is not colored on the surface alone so that the coloreffect is maintained even if the material is which in the production ofthe aggregate material is thoroughly mixed with cement before a noduleformation is performed. Therefore, pigments may be chosen within a widerange, and the aggregate material according to the invention maytherefore be produced with a wide variety of different colors.

Examples of pigments that may be used in the aggregate material aremetal oxides, such as iron oxides, chromium oxides, and cobalt andtitanium nickel compounds.

Instead of producing the colored cement in conjunction with theproduction of the nodules, commercial colored cement, which normallyconsists of a white cement with a it is further possible to replace partof the water by an acrylic polymg; mp n, e.g. the acryl emulsions whichare sold under the trade names Primal MC 4530 Vinacryl 4040 and Lasbetonuniversal acryl.

By introducing an acrylic polymer emulsion into the aggregate materialaccording to the invention instead of part of the water a higher impactstrength may be obtained.

The pigment is preferably used in an amount from 2 to by weight of thecement.

The invention also relates to a process for producing an aggregatematerial of the kind mentioned. According to this process, small bodiesof devitrified glass are moistened with water, a mixture ofcementaid'big'ment is added while at the same time stirring, and theproduct thereby formed is placed on a moving surface for the productionof nodules, the nodules thus formed being removed from the movingsurface when they have reached the desired size.

During the stay on the moving surface, a nodule forma tion takes placeby virtue of the so-called snow-ball-effect, i.e. small bodies ofdevitrified glass and cement. with pigment added thereto will continueto adhere to the surface of the agglomerates of moistened small bodiesof devitrified glass and cement first formed.

The nodule formation is preferably effected on the inner face of a drumrotating about a horizontal axis or on the inner side of a horizontallydisposed container performing a reciprocating movement.

After the nodules have been formed, these may be introduced into achamber containing moist air or be stored in water. Alternatively theymay be subjected to autoclave treatment to promote setting.

The invenion will now be further illustrated with reter ence to anexample indicating various embodiments of the aggregate materialaccording to the invention and one embodiment of the method of makingsaid material.

EXAMPLE- A series of aggregate materials were made from the componentslisted in the table below. The process was carried out as follows: Waterwas added to a dry mass of small bodies of devitrified glass so that thelatter was slightly moistened and then a mixture of cement and pigmentwas sprinkled onto the moistened small bodies while at the same timestirring. The mixture thus formed was introduced into a rotatingcontainer whereby nodules were formed. The nodules were stored for 28days in water at a temperature of 18 C. and were then placed on traysfor drying in the air at 18 C. for three days.

Finally, the nodules thus formed were subjected to a test fordetermining the crushing-down figure of the nodules as follows: A sampleof 500 g. of the material having a grain size of 5-7 mm. was subjectedto 20 impacts from a drop-hammer. Thereafter the material was sievedthrough sieves having mesh sizes of 5, 4, 3, 2 and 1 mm. respectively.The quantities of material passing through the sieve of 1 mm. mesh sizeand the quantities of material retained on the sieves having the meshsizes 1, 2, 3, and 4 respectively were weighed and expressed inpercentages of the starting material. These percentages are designatedA, B, C, D, and E and the crushing-down figure N is determined by theequation The results obtained will be apparent from the below table.

Composition and crushing down figure of various aggregate materialsaccording to the invention.

Crushingdown Test No. Composition figure.

1 1 kg. white cement, 2 kg. devitrified glass (particle size 1-2 mm.),.05 kg. yellow pigment, 0.44 kg. water 35 2 1 kg white cement 2kg.devitrified glass (particle size 1-2 mi, .10 kg. green pigment, .44 kg.watch"... 53 3 1 kg. white cement, 2 kg. devitrified glass (partiolesize 1-2 mm.), .05 kg. blue sigment, .44 kg. water 42 4 1 kg. redcement, 2 kg. devitrified glass particle size12mm.), .44 kg. water 56 5.1 kg. green cement, 2 kg. devitrified glass (particle size 1-2 mm), .44kg. water 51 6 1 kg. red cement, 2 kg. devitrified glass (particle size1-2 mm.), .2 kg. Primal M04530 .25 kg. water 18 7. 1 kg. red cement, 2kg. devitrified glass (particle size 1-2 mm.), .1 kg. Vlnacryl 4040, .32kg. water 27 8. 1 kg. red cement, 2 kg. devitrified glass (particle size1-2 mm), .05 kg. Lasbeton universal acryl, .41 kg. water 35 It will beapparent from the above results that the nodules forming the aggregatematerial according to the invention have a high impact strength. By wayof comparison the devitrified glass material marketed under the tradename Synopal has a crushing-down figure of 20-35.

It will also be seen that the replacing part of the water by an acrylicpolymer emulsion, a lower crushing-down figure, i.e. a higher impactstrength, is obtained.

What I claim is:

1. A synthetic aggregate material particularly for use in moldable roadsurface coatings comprising a major proportion of nodules of smallbodies of dgyitrified glass and minor proportions of hydrggliealmetgement and pTgment.

2. A process as in claim 6 wherein the small bodies of devitrified glassare produced by quenching of molten glass.

3. A synthetic aggregate material according to claim 1, wherein theweight ratio of devitrified glass to cement is about 2:1.

4. A synthetic aggregate material according to claim 1 wherein saidpigment. is present in an amount of from about 2 to 10% by weight basedon the weight of cement.

5. A synthetic aggregate material according to claim 1 wherein thenodules have a grain size of 4-12 mm.

6. A process for producing amid comprising the steps of moistening smallbodies of devitrified glass with water, adding a mixture of cement andpigment while at the same time stirring, placing the product thusobtained on said moving surface to produce nodules, and removing saidnodules from said moving surface after they have reached a desired size.

References Cited UNITED STATES PATENTS JAMES E. POER, Primary ExaminerU.S. Cl. X.R. 106-64, 97

